Pedal assembly having force sensing

ABSTRACT

A pedal assembly includes an upper housing member separated from a lower housing member defining a cavity. The pedal arm is configured to move within the cavity and apply a force to the upper housing member. A pair of fixed magnets are attached to the upper and lower housing. Both of the fixed magnets are orientated with similar polarity facing in the same direction. A moveable magnetic is positioned between the pair of fixed magnets, the moveable magnet positioned with a polarity that is opposite of the pair of fixed magnets. A magnetic sensor is positioned in the housing. When a load is applied to the pedal arm, the pedal arm applies a force to the upper housing member moving the moveable magnet in the housing wherein the magnetic sensor senses movement of the moveable magnet indicative of the amount of depression of the pedal arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This utility patent application claims priority benefit from U.S.Provisional Patent Application Ser. No. 63/309,817, filed Feb. 14, 2022and entitled “Pedal Pad Force Sensors”, the entire contents of which isincorporated herein in its entirety.

TECHNICAL FIELD

The present specification generally relates to pedal assemblies forvehicles and, more specifically, to force sensing pedal assemblies.

BACKGROUND

Conventional pedal assemblies include a pedal arm that is pivotallycoupled to a housing at one end and a pedal pad positioned on anopposite end. In these pedal assemblies, various inductive or HallEffect type sensors are positioned within the housing to measure theamount of pivot of the pedal arm with respect to the a target. When aforce is applied to the pedal pad, the pedal arm pivots and, based onthe amount of pivot, generally electric motors control the vehicleaccordingly. However, in floor mounted pedal pads, a user may not applythe same pressure or load over the entire pedal pad. As such, loadbalancing and measuring small amount of travel of the pedal arm areissues.

SUMMARY

In one aspect, a pedal assembly includes a housing having a cavity. Thehousing includes an upper housing member separated from a lower housingmember. A pedal arm is at least partially received in the cavity. Thepedal arm is configured to move within the cavity relative to thehousing and apply a force to the upper housing member. A pair of fixedmagnets are fixedly attached to the upper housing member and to thelower housing member respectively. Both of the fixed magnets areorientated with similar polarity facing in the same direction. Amoveable magnetic is positioned between the pair of fixed magnets, themoveable magnet positioned with a polarity that is opposite of the pairof fixed magnets. A magnetic sensor is positioned in the housing. When aload is applied to the pedal arm, the pedal arm applies a force to theupper housing member moving the moveable magnet in the housing whereinthe magnetic sensor senses movement of the moveable magnet indicative ofthe amount of depression of the pedal arm.

In another aspect, a pedal assembly includes a housing having a cavity.The housing includes an upper housing member separated from a lowerhousing member. A pedal arm is at least partially received in thecavity. The pedal arm is configured to move within the cavity relativeto the housing and apply a force to the upper housing member. A biasingmember is positioned between the pedal arm and the upper housing. A pairof fixed magnets are fixedly attached to the upper housing member and tothe lower housing member respectively. Both of the fixed magnets areorientated with similar polarity facing in the same direction. Amoveable magnetic is positioned between the pair of fixed magnets, themoveable magnet positioned with a polarity that is opposite of the pairof fixed magnets. A magnetic sensor is positioned in the housing. When aload is applied to the pedal arm, the pedal arm applies a force to theupper housing member moving the moveable magnet in the housing whereinthe magnetic sensor senses movement of the moveable magnet indicative ofthe amount of depression of the pedal arm.

In a further aspect, a pedal assembly includes a housing having acavity. The housing includes an upper housing member separated from alower housing member. A pedal arm is at least partially received in thecavity. The pedal arm is configured to move within the cavity relativeto the housing and apply a force to the upper housing member. A biasingmember is positioned between the pedal arm and the upper housing. Astrain gauge sensor is attached to the biasing member. A pair of fixedmagnets are fixedly attached to the upper housing member and to thelower housing member respectively. Both of the fixed magnets areorientated with similar polarity facing in the same direction. Amoveable magnetic is positioned between the pair of fixed magnets, themoveable magnet positioned with a polarity that is opposite of the pairof fixed magnets. A magnetic sensor is positioned in the housing. When aload is applied to the pedal arm, the pedal arm applies a force to theupper housing member moving the moveable magnet in the housing whereinthe magnetic sensor senses movement of the moveable magnet indicative ofthe amount of depression of the pedal arm and wherein the strain gaugesensor is configured to sense an amount of deflection of the biasingmember indicative of the amount of depression of the pedal arm.

These and additional features provided by the embodiments describedherein will be more fully understood in view of the following detaileddescription, in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments set forth in the drawings are illustrative and exemplaryin nature and not intended to limit the subject matter defined by theclaims. The following detailed description of the illustrativeembodiments can be understood when read in conjunction with thefollowing drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 depicts a perspective view of a pedal assembly according to oneor more embodiments shown and described herein;

FIG. 2A depicts a sectional view of the pedal assembly of FIG. 1 in anun-applied position according to one or more embodiments shown anddescribed herein;

FIG. 2B depicts a sectional view of the pedal assembly of FIG. 1 in anapplied position according to one or more embodiments shown anddescribed herein;

FIG. 3 depicts a front view of magnets of the pedal assembly of FIG. 1with the housing and spring cup removed according to one or moreembodiments shown and described herein;

FIG. 4 depicts a perspective view of top housing according to one ormore embodiments shown and described herein;

FIG. 5 depicts a perspective view of bottom housing according to one ormore embodiments shown and described herein;

FIG. 6 depicts a side view of top housing and pedal arm according to oneor more embodiments shown and described herein;

FIG. 7 depicts a side view of top housing and pedal arm according to oneor more embodiments shown and described herein;

FIG. 8 schematically depicts a block diagram of the circuit boardschematic of the pedal assembly of FIG. 1 according to one or moreembodiments shown and described herein;

FIG. 9 schematically depicts a block diagram of a signal processing ofone example strain gauge senor of the pedal assembly of FIG. 1 accordingto one or more embodiments shown and described herein.

DETAILED DESCRIPTION

Embodiments described herein are directed to a pedal assembly thatincludes a pedal arm movably positioned within a cavity of a housing. Aproximal end of the pedal arm includes a pedal pad. Three magnets arepositioned within the cavity. A magnet sensor is positioned in thehousing. The magnet sensor is configured to sense an amount of movementof a middle of the three magnets. A biasing member is positioned betweenthe pedal arm and the top housing. A strain gauge sensor is attached tothe biasing member. The strain gauge sensor is configured to sense anamount of the deflection of the biasing member. Various embodiments ofthe pedal assembly are described in detail herein.

As used herein, the term “communicatively coupled” means that coupledcomponents are capable of exchanging data signals with one another suchas, for example, electrical signals via conductive medium or anon-conductive medium, though networks such as via Wi-Fi, Bluetooth, andthe like, electromagnetic signals via air, optical signals via opticalwaveguides, and the like.

As used herein “minimal travel” or “reduced travel” or “limited travel”may be interchangeability used and refer to a pedal stroke of the pedalarm needed or required to detect the amount of load or force of the loadapplied to the pedal pad. In minimal travel pedal applications, thetotal travel of the pedal arm is 30 millimeters or less. As such,sensing the amount of travel of the pedal arm in these minimal travelapplications for brake-by-wire applications must be precise due to thelimited amount of pedal stroke. Load balancing of the pedal arm isdesirable to detect a load applied to any portion of the pedal padwithout the need for a direct center contact of the pedal pad. As such,the aspects of the pedal assemblies described herein are directed tominimal travel pedal assemblies with load balancing and strain gaugesensing that is more sensitive to the load applied to the pedal pad andis immune to load offset to sense any movement of the pedal armregardless of where the load is applied to on the pedal pad.

As used herein, the term “longitudinal direction” refers to theforward-rearward direction of the pedal assembly (i.e., in the+/−X-direction depicted in FIG. 1 ). The term “lateral direction” refersto the cross-pedal assembly direction (i.e., in the +/−Y-directiondepicted in FIG. 1 ), and is transverse to the longitudinal direction.The term “vertical direction” or “up” or “above” or “below” refer to theupward-downward direction of the pedal assembly (i.e., in the+/−Z-direction depicted in FIG. 1 ).

Referring initially to FIGS. 1-7 , a pedal assembly 10 is depicted. Thepedal assembly 10 includes a housing 12, and a pedal arm assembly 14.The housing 12 includes a lower housing member 16 and an upper housingmember 18. The upper housing member 18 includes an opening 20 formedtherein allowing passage of a portion of the pedal arm assembly 14.

Referring to FIG. 4 , the upper housing member 18 includes a firstcircular body 22 having an upper cavity 24 formed therein. The circularbody 22 includes the opening 20. Around a rim 26 of the circular body 22a plurality of holes 28 are formed therein that receive pins 30 of thelower housing 16 as will be described in more detail below.

Referring to FIG. 5 , the lower housing member 16 includes a secondcircular body 32 having a lower cavity 34 formed therein. The circularbody 32 includes a second opening 36 allowing passage of the pedal arm24. Around a rim 38 of the circular body 32 a plurality of pins 30 areattached thereon to pass through the holes 28 in the upper housing 18 asdescribed above.

The housing 12 may be formed of steel or other metal. Alternatively, thehousing 12 may be formed of a molded plastic. For example, the housing12 may be formed with various materials such as acrylonitrile butadienestyrene (ABS), polyethylene (PE), polypropylene (PP), polycarbonate(PC), nylon, polycarbonate/acrylonitrile butadiene styrene,polyurethane, polymethyl methacrylate, high density polyethylene, lowdensity polyethylene, polystyrene, PEEK, POM (Acetal/Delrin),polyethylene terephthalate, thermoplastic elastomer, polyetherimide,theremoplastic vulcanizate, polysulfone, combinations thereof, and/orthe like. Additionally, additives may be added such as UV absorbers,flame retardants, colorants, glass fibers, plasticizers and/or the like.

Referring to FIGS. 2A, 2B, 6 and 7 , the pedal arm assembly 14 includesa pedal arm 40 which includes a pedal pad portion 42 that extends alonga shank 44. The shank 44 may include threads 46 formed thereon to engagewith a stop nut 48. The stop nut 48 may be utilized to define an amountof travel of the shank 44 within the housing 12. The housing 12 may befloor mounted. That is, in some embodiments, the housing 12 may becoupled or mounted to be positioned within or extending from a floorsurface of a vehicle. As such, the cavity 50 of the housing 12accommodates the pedal arm 40 at full depression to allow the pedal pad42 to fully travel.

In some embodiments, the pedal pad 42 is generally circular shaped. Itshould be realized that various shaped pedal pads 42 may be utilizedother that those shown in the depicted embodiment. In one aspect, thepedal pad 42 engages a foot of a user and can depress against to brake,accelerate, and/or activate a clutch control.

Referring to FIGS. 1, 2A and 2B, a biasing member 52 is positionedbetween the upper housing 18 and the pedal arm 40. In the depictedembodiment the biasing member 52 has a conical shape that tapers as itapproaches the upper housing 18. The biasing member 52 includes anopening 54 formed therein allowing passage of the shank 44. A straingauge sensor 68 is provided that is coupled to biasing member 52 and isconfigured to sense an amount of the deflection of the biasing member52.

Referring to FIGS. 2A, 2B and 3 , three magnets 56 are positioned in thecavity 50 defined between the upper and lower housings 18, 16. A pair offixed magnets 58 are positioned within the upper housing 18 and lowerhousing 16 respectively. Both of the fixed magnets 58 are fixedlyattached to the upper housing 18 and lower housing 16 and both fixedmagnets 58 are orientated with similar polarity facing in the samedirections. This provides a repelling force to the middle magnet 60 andas a result force linearity is improved. The middle magnet 60 ismoveable within the housing 12 between the pair of fixed magnets 58 andis positioned with a polarity that is opposite of the pair of fixedmagnets 58. A magnet sensor 62 is positioned in the housing 12 and isconfigured to determine movement of the moveable magnet 60.

The magnet sensor 62 detects movement of the moveable magnet. In someembodiments, the magnet sensor 62 includes a printed wiring assembly anda connector housing 64. The printed wiring assembly may include acircuit board (or a printed circuit board), which may include at leastone Asic 66.

While an embodiment above describes the use of a biasing member 52 totransfer a force to the upper housing member 18, it should be realizedthat other structures may be utilized. For example the pedal arm may bedirectly coupled to the upper housing to apply a force to the upperhousing. In such an application the strain gauge 68 may be removed fromthe pedal assembly.

Now referring to FIG. 8 , a block diagram of the circuit board schematicof the pedal assembly 10 is schematically depicted. As depicted, astrain gauge sensor 68 is communicatively coupled to the circuit board70 b while the magnetic sensor 62 is communicatively coupled to thecircuit board 70 a. The circuit board 70 b is communicatively coupled tothe connector 64 b while the circuit board 70 a is communicativelycoupled to the connector 64 a. As such, data communication between thestrain gauge sensor 68 and magnetic sensor 62 to the electronic controlunit on the vehicle side is established via the connectors 64 a, 64 b.Further, such an arrangement permits for a redundancy in sensing anyload applied to anywhere on the pedal pad 42 and provides a desirablefail-safe should any of the magnetic sensor 62 or strain gauge sensor 68and/or circuit boards 70 a, 70 b or components thereof fail.

In one aspect, the sensors 62, 68 output a digital signal to theconnector 70 a or 70 b for example, indicative of the current amount oftravel of the pedal arm 40. As such, the strain gauge sensor 68 andmagnetic sensor 62 provide an improvement over conventional systems byproviding a precise measurement to any load applied to any portion ofthe pedal pad 42. That is, the user does not have to center contact withthe pedal pad 26 and the load may be applied to any portion of the pedalpad 26. Further, the arrangement of the sensors 62, 68 provide a precisesensing in applications where the pedal pad 42 and pedal arm 40 have aminimal travel.

Further, each of the corresponding sensors 62, 68 provide a redundancyin sensing capabilities. As depicted in FIG. 8 , the strain gauge sensor68 is communicatively coupled to the circuit board 70 b while themagnetic sensor 62 is communicatively coupled to the circuit board 70 a.Such an arrangement permits for a redundancy in sensing any load appliedto anywhere on the pedal pad 42 and provides a desirable fail-safeshould any of the sensors and/or circuit boards or components thereoffail.

Now referring to FIG. 9 , an example application specific integratedcircuit (asic) or signal processing of the data sensed by the straingauge sensor 68 of the example pedal assembly 10 is schematicallydepicted.

As depicted, the strain gauge sensor 68 may be a full bridge straingauge such as a piezoresistive sensing element 1305, arranged as abridge circuit, and communicatively coupled to a programmable-gainamplifier 1310 and to an analog supply voltage as a VDDA 1315 and outputas a divided bridge current though a converter 1320 into a multiplexer1325. The output from the programmable-gain amplifier 1210 is the secondinput into the multiplexer 1325, which is then transmitted to ananalog-to-digital converter 1330 and is transmitted as an digital signalinto the digital signal processor 1335, which outputs a digital signal1340 to the connector 64 b, for example, indicative of the currentamount of deflection or bend applied to the biasing member 52.

In operation, when the pedal pad 42 is depressed the pedal arm 42 movesand compresses the biasing member against the upper housing. The amountof force applied to the biasing member and amount of deflection of thebiasing member is detected by the strain gauge sensor 68.

The force is transferred to the upper housing which moves downwardly.The upper housing moves along the pins of the lower housing in acontrolled manner. The fixed magnet disposed in the upper housingapplies a force to the movable magnetic which also moves downwardlyagainst the biasing force of the fixed magnet in the lower housing togenerate a force feedback to a foot on the pedal pad 42. Movement of themoveable magnet is detected by the magnetic sensor as described above.Such an arrangement permits for a redundancy in sensing any load appliedto anywhere on the pedal pad 42 and provides a desirable fail-safeshould any of the sensors and/or circuit boards or components thereoffail.

It is noted that the terms “substantially” and “about” may be utilizedherein to represent the inherent degree of uncertainty that may beattributed to any quantitative comparison, value, measurement, or otherrepresentation. These terms are also utilized herein to represent thedegree by which a quantitative representation may vary from a statedreference without resulting in a change in the basic function of thesubject matter at issue.

While particular embodiments have been illustrated and described herein,it should be understood that various other changes and modifications maybe made without departing from the spirit and scope of the claimedsubject matter. Moreover, although various aspects of the claimedsubject matter have been described herein, such aspects need not beutilized in combination. It is therefore intended that the appendedclaims cover all such changes and modifications that are within thescope of the claimed subject matter.

1. A pedal assembly comprising: a housing having a cavity, the housingincluding an upper housing member separated from a lower housing member;a pedal arm at least partially received in the cavity, the pedal armconfigured to move within the cavity and apply a force to the upperhousing member; a pair of fixed magnets fixedly attached to the upperhousing member and to the lower housing member respectively, and bothfixed magnets are orientated with similar polarity facing in the samedirection; a moveable magnetic positioned between the pair of fixedmagnets the moveable magnet positioned with a polarity that is oppositeof the pair of fixed magnets, a magnetic sensor positioned in thehousing; wherein when a load is applied to the pedal arm, the pedal armapplies a force to the upper housing member moving the moveable magnetin the housing wherein the magnetic sensor senses movement of themoveable magnet indicative of the amount of depression of the pedal arm.2. The pedal assembly of claim 1, including a biasing member positionedbetween the pedal arm and the upper housing.
 3. The pedal assembly ofclaim 2 wherein the biasing member includes a conical shape that tapersin a direction toward the upper housing.
 4. The pedal assembly of claim2 including a strain gauge sensor attached to the biasing member andconfigured to sense an amount of deflection of the biasing member. 5.The pedal assembly of claim 1, wherein the housing is mounted to afloor.
 6. The pedal assembly of claim 1 wherein the upper housing memberincludes a first circular body having an upper cavity formed therein,the first circular body including a rim having a plurality of holesformed therein.
 7. The pedal assembly of claim 6 wherein the lowerhousing member includes a second circular body having a lower cavityformed therein, the second circular body including a rim having aplurality of pins attached thereon to pass through the holes in theupper housing.
 8. A pedal assembly comprising: a housing having acavity, the housing including an upper housing member separated from alower housing member; a pedal arm at least partially received in thecavity, the pedal arm configured to move within the cavity and apply aforce to the upper housing member; a biasing member positioned betweenthe pedal arm and the upper housing; a pair of fixed magnets fixedlyattached to the upper housing member and to the lower housing memberrespectively, and both fixed magnets are orientated with similarpolarity facing in the same direction; a moveable magnetic positionedbetween the pair of fixed magnets the moveable magnet positioned with apolarity that is opposite of the pair of fixed magnets, a magneticsensor positioned in the housing; wherein when a load is applied to thepedal arm, the pedal arm applies a force to the upper housing membermoving the moveable magnet in the housing wherein the magnetic sensorsenses movement of the moveable magnet indicative of the amount ofdepression of the pedal arm.
 9. The pedal assembly of claim 8 whereinthe biasing member includes a conical shape that tapers in a directiontoward the upper housing.
 10. The pedal assembly of claim 8 including astrain gauge sensor attached to the biasing member and configured tosense an amount of deflection of the biasing member.
 11. The pedalassembly of claim 8, wherein the housing is mounted to a floor.
 12. Thepedal assembly of claim 8 wherein the upper housing member includes afirst circular body having an upper cavity formed therein, the firstcircular body including a rim having a plurality of holes formedtherein.
 13. The pedal assembly of claim 12 wherein the lower housingmember includes a second circular body having a lower cavity formedtherein, the second circular body including a rim having a plurality ofpins attached thereon to pass through the holes in the upper housing.14. A pedal assembly comprising: a housing having a cavity, the housingincluding an upper housing member separated from a lower housing member;a pedal arm at least partially received in the cavity, the pedal armconfigured to move within the cavity and apply a force to the upperhousing member; a biasing member positioned between the pedal arm andthe upper housing; a strain gauge sensor attached to the biasing member;a pair of fixed magnets fixedly attached to the upper housing member andto the lower housing member respectively, and both fixed magnets areorientated with similar polarity facing in the same direction; amoveable magnetic positioned between the pair of fixed magnets themoveable magnet positioned with a polarity that is opposite of the pairof fixed magnets, a magnetic sensor positioned in the housing; whereinwhen a load is applied to the pedal arm, the pedal arm applies a forceto the upper housing member moving the moveable magnet in the housingwherein the magnetic sensor senses movement of the moveable magnetindicative of the amount of depression of the pedal arm and wherein thestrain gauge sensor is configured to sense an amount of deflection ofthe biasing member indicative of the amount of depression of the pedalarm.
 15. The pedal assembly of claim 14 wherein the biasing memberincludes a conical shape that tapers in a direction toward the upperhousing.
 16. The pedal assembly of claim 14, wherein the housing ismounted to a floor.
 17. The pedal assembly of claim 14 wherein the upperhousing member includes a first circular body having an upper cavityformed therein, the first circular body including a rim having aplurality of holes formed therein.
 18. The pedal assembly of claim 17wherein the lower housing member includes a second circular body havinga lower cavity formed therein, the second circular body including a rimhaving a plurality of pins attached thereon to pass through the holes inthe upper housing.